1. Field of the Invention
The present invention generally relates to digital image processing, and more particularly to a system and method of revising depth generated based on a three-dimensional (3D) image pair.
2. Description of Related Art
When three-dimensional (3D) objects are mapped onto a two-dimensional (2D) image plane by prospective projection, such as an image taken by a still camera or a video camera, a lot of information, particularly 3D depth information, disappears. A 3D imaging system, however, can convey 3D information to a viewer by recording 3D visual information or by re-creating the illusion of depth. Although the 3D imaging technique has been known for over a century, the 3D display becomes more practical and popular owing to availability of high-resolution and low-price displays such as liquid crystal displays (LCDs).
FIG. 1 shows a block diagram of a conventional 3D imaging system 1 that creates depth information by a depth generator 11 according to a 2D image input. The depth information is then processed by the depth-image-based rendering (DIBR) 12 to generate a left (L) image 14A and a right (R) image 14B, which are then displayed and viewed by the viewer.
Moreover, FIG. 2 shows a block diagram of another conventional 3D imaging system 2 that captures a left (L) image 20A and a right (R) image 20B from a target object by two cameras respectively. The depth generator 21 utilities stereo matching technique such as block matching to acquire the left and right depth information from a stereo image pair, L image 20A and R image 20B, respectively. The left and right depth information is then processed by the depth-image-based rendering (DIBR) 22 to generate at least two images with different viewpoint (i.e., at least one left (L′) image 24A and at least one right (R′) image 24B), which should be viewed by the viewer, according to the matching relation of the L image 20A and R image 201B.
However, for the conventional 3D imaging system 2, there are still some basic constraints in stereo videos, such as occlusion, two-camera setting parameter deviation, which may affect the generated depth information. Therefore, if only considering the matching relation of the stereo image pair, some pixels are probably induced to the unreliable depth information.
For the reason that conventional 3D imaging systems could not effectively display 3D image or video, a need has arisen to propose a novel system and method of revising depth of a 3D image that could recapture or generate 3D depth information, to faithfully and easily recover or approximate a full 3D representation.